Batteries typically comprise one or a connected set of similar units or cells acting as an electrical energy source. Most batteries operate by converting chemical energy directly into electrical energy. However, while chemical batteries are typically inexpensive to produce and may supply a reasonably high energy output, they may not be compatible with, for example, microelectronic devices due to size and durational requirements.
Other batteries generally referred to as nuclear or radioisotope batteries have been developed, which directly or indirectly convert radioactive energy released during the decay of a radioactive source into electrical energy. For instance, in some radioisotope batteries, a radioactive source emits nuclear radiation, e.g. alpha or beta particles, which produces electron-hole pairs within a planar semiconductor material. The movement of these charges over times results in an electronic current, which when connected to a load resistor operates as a source of power. However, such conventional planar radioisotope batteries often suffer efficiency, flexibility, scalability and low output power in the microwatt range.